Blar i Articles på emneord "bestandsberegning"
Viser treff 1-16 av 16
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A new model for simulating growth in fish
(Journal article; Peer reviewed, 2014-01-16)A real dynamic population model calculates change in population sizes indepen- dent of time. The Beverton & Holt (B&H) model commonly used in fish assessment includes the von Bertalanffy growth function which has age or ... -
Abundance estimation of Northeast Atlantic mackerel based on tag recapture data - A useful tool for stock assessment?
(Journal article; Peer reviewed, 2010-10)In the present study we utilize tag recapture data to estimate year class abundance and spawning stock biomass of mackerel (Scomber scombrus L.) in the Northeast Atlantic for the period 1986–2008. On average 20,000 jigged ... -
Application of evolutionary theory to fisheries science and stock assessment-management
(Others, 2000-12-08) -
Bestandsundersøkelser og forslag til regulering av loddefisket i området lsland-Grønland-Jan Mayen i 1979
(Journal article, 1979-10-15)Sommeren 1978 begynte norske ringnotfartøyer å fiske lodde i området mellom Jan Mayen og Grønland. Dette er lodde som gyter ved Island om vinteren, og som beiter i området mellom Island, Grønland og Jan Mayen om sommeren. ... -
Biomass of Scyphozoan Jellyfish, and Its Spatial Association with 0-Group Fish in the Barents Sea
(Journal article; Peer reviewed, 2012-03-22)An 0-group fish survey is conducted annually in the Barents Sea in order to estimate fish population abundance. Data on jellyfish by-catch have been recorded since 1980, although this dataset has never been analysed. In ... -
Determinants of mean length at age of spring spawning herring off the coast of Hokkaido, Japan
(Journal article; Peer reviewed, 2008-08-29)The stock of Hokkaido spring spawning herring Clupea pallasii collapsed in the middle of the 20th century. In the first half of the 20th century, large amounts of spawning herring were caught by set nets at coastal ... -
Distribution and density of goldsinny wrasse (Ctenolabrus rupestris) (Labridae) in the Risør and Arendal areas along the Norwegian Skagerrak coast
(Journal article; Peer reviewed, 2002-03)Samples of fish were collected in the Arendal and Risør areas on the Norwegian Skagerrak coast during the period 1986 to 1990 using a beach seine at 36 different locations. In the Risør area, 131 out of 254 hauls yielded ... -
Distribution, Population Biology, and Trophic Ecology of the Deepwater Demersal Fish Halosauropsis macrochir (Pisces: Halosauridae) on the Mid-Atlantic Ridge
(Journal article; Peer reviewed, 2012-02-22)Halosauropsis macrochir ranked amongst the most abundant and widespread demersal fishes on the mid-Atlantic Ridge of the North Atlantic (Iceland-Azores) with greatest abundance at 1700–3500 m. All sizes, ranging from 10–76 ... -
Estimation of Pup Production of Hooded and Harp Seals in the Greenland Sea in 2007: Reducing Uncertainty Using Generalized Additive Models
(Journal article; Peer reviewed, 2010-02-11)The pup production of the Greenland Sea populations of hooded and harp seals were assessed in aerial surveys using two aircrafts for reconnaissance flights and photographic surveys along transects over the whelping areas ... -
Fisheries-induced trends in reaction norms for maturation in North Sea plaice
(Journal article; Peer reviewed, 2003-08-07)We analyse how intensive exploitation may have caused evolutionary changes in the age and length at maturation in North Sea plaice Pleuronectes platessa. Such evolutionary change in the onset of maturation is expected, ... -
Functional relationship between harp seal body condition and available prey in the Barents Sea
(Journal article; Peer reviewed, 2013-06-12)The Barents Sea ecosystem has undergone substantial ecological fluctuations over the past 40 yr, including large variations in the abundance of capelin Mallotus villosus, herring Clupea harrengus, krill Thysanoessa sp. and ... -
Non-linear dynamics in marine-phytoplankton population systems
(Journal article; Peer reviewed, 2004-06-08)Although non-linear density-dependence has been widely emphasized in population dynamics studies, the existence of non-linear exogenous forces have been less explored. In articular, we propose that the formulation of ... -
Ocean Acoustic Waveguide Remote Sensing (OAWRS) of marine ecosystems
(Journal article; Peer reviewed, 2009-12-03)Ocean Acoustic Waveguide Remote Sensing (OAWRS) has recently been shown to be capable of instantaneously imaging and continuously monitoring fish populations over continental shelf-scale areas, covering thousands of km2. ... -
Seabird−fish interactions: the fall and rise of a common guillemot Uria aalge population
(Journal article; Peer reviewed, 2013-02-14)A major challenge in population ecology is the prediction of population responses to environmental variance. Food availability has long been hypothesized to play a major role in regulating seabird populations. In general, ... -
Tallrikhetsmåling - innsats og pålitelighet
(Fisken og havet, Research report, 1996)Hvordan avhenger presisjonen i tallrikhetsanslagene fra tokt av selve toktinnsatsen; i.e. av utseilt distanse og antall trålstasjoner eller fartøydøgn? Spørsmålet er belyst med eksempler fra litteraturen og fra vintertoktene ... -
Towards the acoustic estimation of jellyfish abundance
(Journal article; Peer reviewed, 2005-06-23)Acoustic target strengths (TSs) of the 2 most common large medusae, Chrysaora hysoscella and Aequorea aequorea, in the northern Benguela (off Namibia) have previously been estimated (at 18, 38 and 120 kHz) from acoustic ...